Posts Tagged ‘quantum reality’

Consensus Quantum Reality

January 15, 2013 1 comment

A paper was recently reported on the Arxiv blog that I feel compelled to comment on. It showed the results of a poll of physicists, philosophers and mathematicians about the nature of quantum reality. It makes a for a fascinating read. One message comes through loud and clear, which anyone can pick up on regardless of their level of scientific knowledge, and that’s that scientists are massively undecided.

I can’t say I’m hugely surprised by this, but I find the results of the poll somewhat disappointing. I don’t often resort to rolling my eyes at mainstream physics, because I believe that digital physics researchers, and computer scientists in general, have a huge amount to learn from the physics community. Furthermore, if digital physicists don’t create tools that can pass muster in the eyes of physics professionals, then, at some level, we haven’t done our job. However, on this occasion, I think eye rolling is in order.

Let’s take question one on the list: What is your opinion about the randomness of individual quantum events? A great question. Kudos to Anton Zellinger and his team for asking it. However, the results are as follows:

  • The randomness is only apparent: 9%
  • There is a hidden determinism: 0%
  • The randomness is irreducible: 48%
  • Randomness is a fundamental concept in nature: 64%

Good lord. Really? Let’s take a moment to ask the question: what is randomness? We can start with a pretty basic definition on Wikipedia. It states that randomness commonly means a lack of pattern or predictability in events.

In other words, we define randomness through a negation. This is true up to and including the most formal definitions of randomness that I’m aware of. We say that something is random when we don’t know what’s going to happen next.

But there’s a deep problem here. Randomness, as we’ve defined it, isn’t a thing. It’s the opposite of a thing. And we have defined it based on the notion of predictability. Except, (as I’ve pointed out in previous posts), prediction is always done with some limited amount of computing power. There is no such thing as an infinitely powerful prediction machine. It’s hard to know what this would even mean.

And any system with limited ability to compute can only pick out and identify a finite number of patterns. For instance, I have the ability to surprise my four-month-old son on a regular basis. However, that does not make my behavior quantum mechanical.

The same limitation is true at any scale you want to pick. The combined computing power of the human race is still limited. There are problems that we can’t solve. Which means that there must be patterns in the universe that we cannot predict, but which can be derived from some underlying deterministic process. In fact, we know that this is true. We’ve been studying problems of this sort since the 1880’s, before quantum mechanics was even invented.

So, in order for someone to propose that randomness is a fundamental concept in nature, they have to assert that even though we know unpredictable deterministic patterns exist, quantum mechanics is not like them. And given that there can be no proof either way, this choice is always made in the absence of information. In other words, it is faith.

I do not like faith in my science. It has no place, IMO. And the only approach that is not faith is to continually doubt. In this case, doubting means assuming that the minimal information model is correct until you have evidence otherwise. In other words, proposing that an underlying mechanism exists and trying to look for such a model until you have a concrete, inviolable reason to believe that one could never be found. In other words, doubting equals determinism–the basis on which we founded science in the first place. (The same answer that received a zero percent vote.)

My concern about this mystic belief in randomness is that it suggests that a great number of physicists, while no doubt highly adept in their respective subfields, have not thought independently about the tools that they are using. They have accepted the notion of implicit randomness because it’s baked into the culture of physics and so it seems foolish to disregard. They believe in implicit randomness because ‘of course there is randomness’, or some mathematically dressed up version of the same. Whichever way you cut it, this is a bad reason.

For further evidence that this lamentable state of affairs does indeed exist, one need look no further than question 12: What is your favorite interpretation of quantum mechanics? Forty-two percent of the respondents picked the Copenhagen Interpretation, making it by far the most popular response.

What, you mean the version dreamt up by a bunch of coffee-swilling logical positivists in the 1920s, while Alan Turing was still in middle-school?

Sheesh. Don’t get me started.